Institute of Biological and Biomedical Sciences
Our current laboratory research
For further details and publication history please see my staff profile
Carbon Nanotubes as drug carriers
Since their discovery in 1991, carbon nanotubes (CNTs) have stimulated a great deal of research aimed at elucidating their properties as well as defining new applications in diverse fields. CNTs are allotropes of carbon and they can be described as a rolled up graphene sheet in which the carbon atoms are found in the sp2 conformation. Depending on the number of graphene sheets concentrically rolled up to form the tubes, these are classified as single-wall nanotubes (SWNTs) or multi-wall nanotubes (MWNTs). CNTs present distinctive properties that have drawn the attention of scientists interested in the development of novel biomaterials for pharmaceutical and medical applications. In particular, their ability to penetrate cell membranes by virtue of their needle like structure makes them of great interest for drug delivery applications. A few issues regarding CNTs have been challenging researchers in the biomedical field, namely low solubility, toxicity and biopersistance. We have recently addressed the low solubility and high tendency to aggregate of CNTs by non-covalent surface modification employing an amphiphilic derivative of chitosan. This polymer is also able to confer biocompatibility. Our polymer wrapped nanotubes are biocompatible and stable; the next step of our research is to demonstrate that they are also biodegradable.
Composite materials for bone regeneration applications
Tissue engineering or tissue regeneration is possible thanks to the development of numerous biomaterials that act as support for the attachment and proliferation of cells able to regenerate the damaged tissue. In the case of bone regeneration, hydroxyapatite (HA) is one of the most used materials due to its similarity to the main component of human bone. However, the mechanical properties of pure HA are not sufficiently high for its use in vivo and composites of various types have been prepared to improve its performance. Our group is looking at the use of composites of HA, chitosan derivatives and carbon nanotubes to improve the biocompatibility, strength and drug delivery properties of bone implants. We have demonstrated that the use of chitosan derivatives in the formulation of composite materials is able to control the kinetics of drug release depending on the molecular weight of the active drug1. Furthermore we are currently studying the impact of the use of CNTs on the properties of these structures.
Collaborators: Dr Dimitris Fatouros
Thermosensitive Hydrogels for nasal administration
Drugs derived from biotechnology such as proteins and peptides pose great delivery challenges as they are easily degraded both during manufacture and in vivo. We have developed a biocompatible thermosensitive hydrogel for the nasal delivery of peptide drugs able to overcome these challenges. The site of administration can guarantee systemic delivery avoiding the major drawbacks of the oral administration; the mucoadhesive formulation obtained by thermo-induced crosslinking of chitosan derivatives favours retention at the site of action while simplifying administration. Our system releases insulin in a controlled manner that promises the possibility of developing a once a day dosage form.
Collaborators: Dr Dimitris Fatouros, Dr Marisa van der Merwe, Dr John Tsibouklis. Prof Paolo Caliceti
PEptide REsearch Network of Excellence (PERENE)
Our research is part of the trans-channel network established for the development of novel and effective delivery systems for the use of peptides in pharmaceutical and cosmetic formulations. We are working at the development of biocompatible nano-carriers able to deliver peptides across biological barriers such as the blood brain barrier or the gastrointestinal mucosa. Nanocapsules are obtained by hydrodynamic atomisation, a novel technique that not only is able to afford control over the size of the particles obtained but also allows for the elimination of organic solvent often used in the formulation of nano-constructs, improving the biocompatibility of the final formulation. Previously developed polysaccharide derivatives will be employed in this project due to their established biocompatibility and biodegradation.
Collaborators: Dr Eugen Barbu, Prof Darek Gorecki